Saturday, December 22, 2012

One of the more colorful vignettes in philosophy is Gibbard and Harper's "Death in Damascus" case:

Consider the story of the man who met Death in Damascus. Death looked surprised, but then recovered his ghastly composure and said, ‘I am coming for you tomorrow’. The terrified man that night bought a camel and rode to Aleppo. The next day, Death knocked on the door of the room where he was hiding, and said I have come for you’.
‘But I thought you would be looking for me in Damascus’, said the man.

‘Not at all’, said Death ‘that is why I was surprised to see you yesterday. I knew that today I was to find you in Aleppo’.

That is, Death's foresight takes into account any reactions to Death's activities.

Now suppose you think that a large portion of the Great Filter lies ahead, so that almost all civilizations like ours fail to colonize the stars. This implies that civilizations almost never adopt strategies that effectively avert doom and allow colonization. Thus the mere fact that we adopt any purported Filter-avoiding strategy S is strong evidence that S won't work, just as the fact that you adopt any particular plan to escape Death indicates that it will fail.

To expect S to work we would have to be very confident that we were highly unusual in adopting S (or any strategy as good as S), in addition to thinking S very good on the merits. This burden might be met if it was only through some bizarre fluke that S became possible, and a strategy might improve our chances even though we would remain almost certain to fail, but common features, such as awareness of the Great Filter, would not suffice to avoid future filters.

Thursday, December 06, 2012

[Cross-posted from Overcoming Bias; edited to remove tactless commentary 2017. Also, the possibility of reducing the misery in factory farming through genetic alteration discussed in this post does not and would not justify factory farming.]

I have spoken with a lot of people who are enthusiastic about the possibility that advanced genetic engineering technologies will improve animal welfare.

But would it really take radical new technologies to produce genetics reducing animal suffering?

Modern animal breeding is able to shape almost any quantitative trait with significant heritable variation in a population. One carefully measures the trait in different animals, and selects sperm for the next generation on that basis. So far this has not been done to reduce animals' capacity for pain, or to increase their capacity for pleasure, but it has been applied to great effect elsewhere.

One could test varied behavioral measures of fear response, and physiological measures like cortisol levels, and select for them. As long as the measurements in aggregate tracked one's conception of animal welfare closely enough, breeders could generate increases in farmed animal welfare, potentially initially at low marginal cost in other traits.

Just how powerful are ordinary animal breeding techniques? Consider cattle:

In 1942, when my father was born, the average dairy cow produced less than 5,000 pounds of milk in its lifetime. Now, the average cow produces over 21,000 pounds of milk. At the same time, the number of dairy cows has decreased from a high of 25 million around the end of World War II to fewer than nine million today. This is an indisputable environmental win as fewer cows create less methane, a potent greenhouse gas, and require less land.

Anderson, who has bred the birds for 26 years, said the key technical advance was artificial insemination, which came into widespread use in the 1960s, right around the time that turkey size starts to skyrocket...
This process, compounded over dozens of generations, has yielded turkeys with genes that make them very big. In one study in the journal Poultry Science, turkeys genetically representative of old birds from 1966 and modern turkeys were each fed the exact same old-school diet. The 2003 birds grew to 39 pounds while the legacy birds only made it to 21 pounds. Other researchers have estimated that 90 percent of the changes in turkey size are genetic.

Moreover, breeders are able to improve complex weighted mixtures of diverse traits: